The ChemCam Instrument Suite on the Mars Science Laboratory (MSL) Rover: Body Unit and Combined System Tests

Abstract

International audienceThe ChemCam instrument suite on the Mars Science Laboratory (MSL) rover Curiosity provides remote compositional information using the first laser-induced breakdown spectrometer (LIBS) on a planetary mission, and provides sample texture and morphology data using a remote micro-imager (RMI). Overall, ChemCam supports MSL with five capabilities: remote classification of rock and soil characteristics; quantitative elemental compositions including light elements like hydrogen and some elements to which LIBS is uniquely sensitive (e.g., Li, Be, Rb, Sr, Ba); remote removal of surface dust and depth profiling through surface coatings; context imaging; and passive spectroscopy over the 240-905 nm range. ChemCam is built in two sections: The mast unit, consisting of a laser, telescope, RMI, and associated electronics, resides on the rover's mast, and is described in a companion paper. ChemCam's body unit, which is mounted in the body of the rover, comprises an optical demultiplexer, three spectrometers, detectors, their coolers, and associated electronics and data handling logic. Additional instrument components include a 6 m optical fiber which transfers the LIBS light from the telescope to the body unit, and a set of onboard calibration targets. ChemCam was integrated and tested at Los Alamos National Laboratory where it also underwent LIBS calibration with 69 geological standards prior to integration with the rover. Post-integration testing used coordinated mast and instrument commands, including LIBS line scans on rock targets during system-level thermal-vacuum tests. In this paper we describe the body unit, optical fiber, and calibration targets, and the assembly, testing, and verification of the instrument prior to launch

ChemCam activities and discoveries during the nominal mission of the Mars Science Laboratory in Gale crater, Mars

“…2, panel G). A preliminary LoD around 5-10% was obtained for SO 3 . The detection of S is particularly important for the identication of calcium sulfates.…”

“…10). In the laboratory, prior to launch, Wiens et al 3 reported on experiments at Mars ambient pressure in a ne-grained soil simulant using JDo-1 (73% of this standard has grain sizes <20 mm). The hole produced by the ight instrument was 1.4 mm in diameter aer 50 pulses and 1.8 mm aer 150 pulses.…”

MAHLI on Mars: lessons learned operating a geoscience camera on a landed payload robotic arm

“…8; Robinson et al, 2013); 8. observations of landscape geomorphology ( Fig. 9) and airborne dust; 9. imaging of other instrument hardware (e.g., the APXS calibration target, the CheMin inlet funnel, the Sample Analysis at Mars (SAM) tunable laser spectrometer (TLS), the Rover Environmental Monitoring System (REMS) ultraviolet (UV) sensor and the ChemCam remote warm electronics box (RWEB)) to support their safety and health (Blake et al, 2013;Edgett et al, 2012;Gómez-Elvira et al, 2012;Wiens et al, 2012;Campbell et al, 2014;Figs. 10-12); and 10. observations of the properties and configuration of eolian dust that settled on natural and rover hardware surfaces (Fig.…”

“…This is onboard focus merge product 0808MH0001930000300748R00. MAHLI periodically images the ChemCam RWEB window, which contains the instrument's laser, telescopic optics and remote microscopic imager (RMI) (Maurice et al, 2012), to detect changes in dust contamination. MAHLI is also sometimes used to image the fiber optic cable that carries ChemCam signals to the spectrometers within the rover body , to look for cable wear.…”

“…Dust-free surfaces are rare but yield best results in determining lithology when imaging on Mars. Areas where wind, the rover's dust removal tool (DRT; Anderson et al, 2012) or the ChemCam Laser Induced Breakdown Spectrometer (LIBS; Wiens et al, 2012) removed the surface dust provided a better science return than dust-covered surfaces (Fig. 13).…”